Superfluid Optomechanics with Phononic Nanostructures

TL;DR

This paper proposes a nanofluidic confinement approach using phononic nanostructures to enhance superfluid 4He optomechanical systems by reducing losses and preserving high quality factors, enabling advanced quantum applications.

Contribution

It introduces a novel implementation of superfluid optomechanics with phononic nanostructures to limit radiation losses and improve resonator quality factors.

Findings

Estimated high quality factors for superfluid resonators.

Numerical simulations confirm loss reduction feasibility.

Broad parameter range supports practical implementation.

Abstract

In quantum optomechanics, finding materials and strategies to limit losses has been crucial to the progress of the field. Recently, superfluid 4He was proposed as a promising mechanical element for quantum optomechanics. This quantum fluid shows highly desirable properties (e.g. extremely low acoustic loss) for a quantum optomechanical system. In current implementations, superfluid optomechanical systems suffer from external sources of loss, which spoils the quality factor of resonators. In this work, we propose a new implementation, exploiting nanofluidic confinement. Our approach, based on acoustic resonators formed within phononic nanostructures, aims at limiting radiation losses to preserve the intrinsic properties of superfluid 4He. In this work, we estimate the optomechanical system parameters. Using recent theory, we derive the expected quality factors for acoustic resonators in different thermodynamic conditions. We calculate the sources of loss induced by the phononic nanostructures with numerical simulations. Our results indicate the feasibility of the proposed approach in a broad range of parameters, which opens new prospects for more complex geometries.